The mobile visual search is a very humane information retrieval manner, is to recognize objects in an image with a computer vision method, and to correlate objects to be recognized in the image with relevant virtual digital information, so that the user can retrieve various relevant information without inputting any keyword. One of the key technologies for the mobile visual search is the technology for detecting interest points in an image, which refers to find a certain amount of flags in the image, these flags are featured in that, these flags also can be detected in another image containing the same object at the same position of the object, even if the two images have different sizes or are taken under different lighting conditions or at different viewpoint.
In the prior art, the device for detecting interest points in an image performs down-sampling on an original image, generates an image pyramid with a series of gradually reduced resolutions; acquires multi-scale images of each layer image in the image pyramid by using a plurality of spatial domain Gaussian filters; acquires a multi-scale Laplacian-of-Gaussian response image of each layer image by using a spatial domain Laplacian filter, and acquires interest points of each layer image according to the multi-scale Laplacian-of-Gaussian response image.
However, in the prior art, after acquiring the multi-scale images of each layer image in the image pyramid by using Gaussian filters, there is a need to buffer the multi-scale image of each layer image in the image pyramid, resulting in more memory consumption and a low detection speed.